ENSEMBLE MARSYAS’s all-Bach programme at the Wigmore Hall on Wednesday 20 July was sadly less than the sum of its parts. The ensemble’s virtuosity was never in doubt, but there was a lack of ease throughout that led the listener to wonder whether the previous two days’ extreme heat had caused rehearsal time to be cut short.

After the Sinfonia from Wir müssen durch viel Trübsal (BWV146), the mezzo-soprano Paula Murrihy sang Bach’s radiant cantata of the soul’s anticipation of death Ich habe genug (BWV82) with clarity and reverence, her recitatives a sincere and simple statement of belief; but the opening aria’s accompanying complex oboe obbligato never quite relaxed into the flow of the music, and was occasionally louder than the singer. They found their form as a duo for the final lilting “Ich freue mich auf meinem Tod”, an all-too-brief glimpse of what might have been.

In the Orchestral Suite No. 4, an early version without trumpets and drums, the bass, and even the viola, overpowered the tune. It was a little like hearing the inner workings of a machine. Whether Peter Whelan, providing sprightly direction from the keyboard, was wise to set so large a bass section against one-to-a-part upper voices is open to debate.

Problems of balance again bedevilled Cantata BWV35, Geist und Seele wird verwirret, in which Bach draws us into the world of the deaf mute healed by Jesus. The virtuoso organist Stephen Farr struggled manfully to be audible against his colleagues. One could hear little in the aria “Gott hat alles wohl gemacht” except the bassoon’s stolid marking of the beat. Even Murrihy’s quiet joy in the final “Ich wünsche nur bei Gott zu leben” was marred by heavy-footed continuo.

A listener at the back during rehearsal could have made all the difference. This was a wasted opportunity.